A rotorcraft, such as a tiltrotor or helicopter, includes at least one rotor mast for driving a rotor hub to transmit forces to the attached blades. Two of the most important objectives in rotorcraft design are safety and weight savings. Despite the objective to make everything on a rotorcraft as light as possible, the primary requirement of safety makes it very difficult to reduce the weight of the rotor mast. The difficulty in reducing the weight of the rotor mast is due to the tremendous loads carried through the rotor mast. Not only must the rotor mast transmit the torque from the transmission to the rotor hub, but the rotor mast must transmit the lift force created by the rotating blades to carry the full weight of the rotorcraft. In addition, the rotor mast is subject to lateral loads created by the movement of the rotorcraft as well as the wind. A traditional rotor mast transmits both the torque and the lift forces through a single rotating shaft. Because the worst possible failure a rotorcraft could suffer is mast failure, existing rotor masts utilize steel components to accommodate the large forces. While steel is very strong, it is also very heavy. Accordingly, a rotor mast that is lighter than steel, without sacrificing any of the safety, is extremely desirable.